Tilt adjusting unit for steering columns

ABSTRACT

A tilt adjusting unit for steering columns prevents a steering column from popping up due to an external impact. The tilt adjusting unit includes a support bracket mounted to a predetermined portion of a vehicle body. A steering column is mounted to a predetermined portion of the vehicle body to tilt relative to the vehicle body. A movable bracket tilts along with the steering column. A connection rod connects the movable bracket to the support bracket. A guide slot is formed on a predetermined portion of the support bracket along a tilting direction of the steering column, with the connection rod passing through the guide slot. A locking unit is provided on a predetermined portion of the connection rod to lock or unlock the movable bracket to or from the support bracket. A crossing plate is mounted to a predetermined portion of the support bracket to rotate around an end of the crossing plate, and has a crossing slot to cross the guide slot, thus allowing the connection rod to pass through both the guide slot and the crossing slot.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of Korean Application No. 2003-528, filed Jan. 6, 2003 and Korean Patent Application No. 2003-529 filed on Jan. 6, 2003 and Korean Patent Application No. 2003-530 filed on Jan. 6, 2003, in the Korean Intellectual Property Office, the disclosures of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates, in general, to a tilt adjusting unit for steering columns and, more particularly, to a tilt adjusting unit for steering columns, which prevents a steering column from popping up due to an external impact.

[0004] 2. Description of the Related Art

[0005] Generally, a steering column for vehicles couples a steering wheel to axles of wheels, and functions to change a moving direction of a vehicle. As a user rotates the steering wheel in a direction, the steering column rotates in the same direction to control directions of the wheels, thus adjusting the moving direction of the vehicle.

[0006] Further, the steering column is constructed to be tiltable up and down, so that a position of the steering wheel is adjusted according to a user's size or preference, by adjusting an angle of the steering column. A hinge shaft is provided on a mid-part or a lower end of the steering column so that the steering column rotates around the hinge shaft. Further, a tilt adjusting unit is provided at a predetermined position around the steering column to guide a tilting motion of the steering column and lock the steering column at an adjusted angle.

[0007] As shown in FIG. 1, a conventional tilt adjusting unit for steering columns includes a mounting bracket 1, first and second support brackets 3, and a movable bracket 4. The mounting bracket 1 is mounted to a predetermined portion of a vehicle body. The first and second support brackets 3 are mounted to the mounting bracket 1 to be placed on left and right sides of a steering column 2. The movable bracket 4 is placed at a position between the first and second support brackets 3, and is secured to the steering column 2, through, for example, a welding process, to tilt along with the steering column 2.

[0008] First and second support parts 5 are provided on left and right edges of the movable bracket 4 to be supported by inner surfaces of the first and second support brackets 3, respectively. Each of the first and second support parts 5 has a through hole 5 a, and a guide slot 3 a is formed through each of the first and second support brackets 3 at a position corresponding to the through hole 5 a. The first and second support brackets 3 and the movable bracket 4 are connected to each other, by an adjusting bolt 6 which passes through the through holes 5 a of the first and second support parts 5 and the guide slots 3 a of the first and second support brackets 3.

[0009] Such a construction makes the adjusting bolt 6 move up and down along the guide slots 3 a when the movable bracket 4 is angled vertically, thus adjusting the angle of the steering column 2 which is secured to the movable bracket 4.

[0010] Further, the adjusting bolt 6 includes a head 6 a and a shank 6 b. The head 6 a is provided at an end of the adjusting bolt 6 to be supported by an outer surface of one of the first and second support brackets 3. The shank 6 b extends from the head 6 a, and passes through the first and second support brackets 3 and the first and second support parts 5 to be outwardly projected from a remaining one of the first and second brackets 3. An external threaded part 6 c is formed on an end of the shank 6 b which passes through the first and second support brackets 3. An adjusting nut 7 having an internal threaded part 7 a engages with the external threaded part 6 c of the adjusting bolt 6. Further, an adjusting lever 8 is fastened to the adjusting nut 7 using a screw 9.

[0011] Thus, when the angle of the steering column 2 is adjusted along the guide slots 3 a, and the adjusting lever 8 rotates to tighten the adjusting nut 7, the adjusting nut 7 presses the first and second support brackets 3. At this time, friction between the first and second support brackets 3 and the movable bracket 4 increases, thus locking the steering column 2 at a desired angle.

[0012] Meanwhile, when a user desires to re-adjust the angle of the steering column 2 in such a state, the adjusting lever 8 rotates in a reverse direction to loosen the adjusting nut 7. At this time, the friction between the first and second support brackets 3 and the movable bracket 4 reduces, thus allowing the angle of the steering column 2 to be adjusted again.

[0013] In the conventional tilt adjusting unit for steering columns, a locking force of the adjusting nut 7 is sufficient to lock the steering column 2, in normal conditions. However, when a large external impact acts on the steering column 2, the locking force of the adjusting nut 7 is insufficient to reliably lock the steering column 2 at a desired angle.

[0014] Thus, when the large external impact due to a collision between vehicles, acts on the steering column 2, the steering column 2 may pop up from a locked position. However, the conventional tilt adjusting unit for steering columns has no unit which more reliably lock the steering column 2 to prevent the steering column 2 from popping up, except the adjusting nut 7.

SUMMARY OF THE INVENTION

[0015] Accordingly, it is an aspect of the present invention to provide a tilt adjusting unit for steering columns, which prevents a steering column from popping up due to an external impact.

[0016] Additional aspects and/or advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

[0017] The above and/or other aspects are achieved by a tilt adjusting unit for steering columns, which includes a support bracket which is mounted to a predetermined portion of a vehicle body, a steering column which is mounted to a predetermined portion of the vehicle body to tilt relative to the vehicle body, a movable bracket which tilts along with the steering column, a connection rod which connects the movable bracket to the support bracket, a guide slot which is formed on a predetermined portion of the support bracket along a tilting direction of the steering column, with the connection rod passing through the guide slot, a locking unit which is provided on a predetermined portion of the connection rod to lock or unlock the movable bracket to or from the support bracket, and a crossing plate which is mounted to a predetermined portion of the support bracket to rotate around an end of the crossing plate, and has a crossing slot to cross the guide slot, thus allowing the connection rod to pass through both the guide slot and the crossing slot.

[0018] The crossing plate may comprise a pair of crossing plates which cross each other.

[0019] The pair of crossing plates may rotate in opposing directions, when the movable bracket tilts.

[0020] The locking unit may include first and second stoppers which are provided on opposite ends of the connection rod, respectively, to prevent the movable bracket from being removed from the support bracket, a rotary unit which is rotatably provided on a predetermined portion of the connection rod between the first and second stoppers, a movable unit which is provided on a predetermined portion of the connection rod so that the movable unit and the rotary unit support each other, and moves along the connection rod as the rotary unit rotates, thus locking or unlocking the movable bracket to or from the support bracket, and a rotation restraining part which is provided on a predetermined portion of either the rotary unit or the movable unit to prevent the rotary unit from rotating when the movable bracket is locked to the support bracket.

[0021] The tilt adjusting unit may further include a first cam face which is provided on one of facing surfaces of the rotary unit and the movable unit which face each other, the first cam face having an inclined part inclined along a circumferential direction of the first cam face, and a second cam face which is provided on a remaining one of the facing surfaces of the rotary unit and the movable unit which face each other, the second cam face having a pressing part to press or release the inclined part according to a rotating direction of the rotary unit.

[0022] The rotation restraining part may be provided at an edge of the inclined part to stop the pressing part.

[0023] The inclined part may have a shape of a depression which is depressed on the first cam face, the pressing part may have a shape of a projection which is projected from the second cam face, and the rotation restraining part may be provided between the edge of the inclined part, which is adjacent to the second cam face, and the first cam face.

[0024] The inclined part may have a shape of a projection which is projected from the first cam face, the pressing part may be provided to receive the inclined part therein, and the rotation restraining part may extend from the edge of the inclined part, which is adjacent to the second cam face, into the pressing part.

[0025] The inclined part may comprise a plurality of inclined parts, and the pressing part may comprise a plurality of pressing parts corresponding to the plurality of inclined parts.

[0026] The movable unit and the connection rod may be provided to be prevented from rotating.

[0027] The movable unit may comprise a pair of movable units provided on opposite sides of the rotary unit, the pair of movable units may include an inner movable unit which is provided at a predetermined position inside the rotary unit, and an outer movable unit which is provided at a predetermined position outside the rotary unit.

[0028] The movable unit may be provided between the rotary unit and the support bracket.

[0029] A bearing may be provided on a side of the rotary unit which is opposite to the movable unit.

[0030] A lever may be provided on a predetermined portion of the rotary unit.

[0031] A friction plate may be provided between the movable bracket and the support bracket to increase a contact surface area between the movable bracket and the support bracket.

[0032] A first friction plate may be provided between the support bracket and one of the pair of crossing plates, and a second friction plate may be provided between the pair of crossing plates, the first and second friction plates increasing contact surface areas between the support bracket and the pair of crossing plates.

BRIEF DESCRIPTION OF THE DRAWINGS

[0033] These and other aspects and advantages of the invention will become apparent and more readily appreciated from the following description of the preferred embodiments, taken in conjunction with the accompanying drawings of which:

[0034]FIG. 1 is a sectional view of a conventional tilt adjusting unit for steering columns;

[0035]FIG. 2 is a sectional view of a tilt adjusting unit for steering columns, according to a first embodiment of the present invention;

[0036]FIG. 3 is an exploded perspective view of the tilt adjusting unit for steering columns of FIG. 2;

[0037]FIG. 4 is a sectional view of a tilt adjusting unit for steering columns, according to a second embodiment of the present invention;

[0038]FIG. 5 is an exploded perspective view of the tilt adjusting unit for steering columns of FIG. 4; and

[0039]FIGS. 6 and 7 are side views to show an operation of crossing plates included in the tilt adjusting unit for steering columns according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0040] Reference will now be made in detail to the present preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. The embodiments are described below in order to explain the present invention by referring to the figures.

[0041] A tilt adjusting unit for steering columns, according to a first embodiment of the present invention, adjusts an angle of a steering column which tilts up and down, thus adjusting a height of a steering wheel which is provided at an upper end of the steering column. As shown in FIGS. 2 and 3, the tilt adjusting unit includes a mounting bracket 10, a steering column 20, and first and second support brackets 31 and 32. The mounting bracket 10 is mounted to a predetermined portion of a vehicle body. The steering column 20 is provided to tilt up and down relative to the vehicle body. The first and second support brackets 31 and 32 extend from the mounting bracket 10 to be placed on left and right sides of the steering column 20, respectively. In this case, the first support bracket 31 is provided to the left side of the steering column 20, and the second support bracket 32 is provided to the right side of the steering column 20.

[0042] Between the first and second support brackets 31 and 32 is provided a movable bracket 40 which is secured to the steering column 20 to tilt along with the steering column 20. A cover member 21 covers the steering column 20, and the movable bracket 40 is secured to the cover member 21 of the steering column 20 through, for example, a welding process.

[0043] First and second support parts 41 extend from left and right edges of the movable bracket 40 to be supported by inner surfaces of the first and second support brackets 31 and 32, respectively. Each of the first and second support parts 41 has a through hole 43 at a predetermined portion thereof, and a guide slot 33 is formed along a tilting direction of the steering column 20 through each of the first and second support brackets 31 and 32 at a position corresponding to the through hole 43. The first and second support brackets 31 and 32 and the movable bracket 40 are connected to each other by a connection rod 50 which passes through the through holes 43 of the first and second support parts 41 and the guide slots 33 of the first and second support brackets 31 and 32.

[0044] Thus, when the movable bracket 40 tilts up and down, the connection rod 50 moves up and down along the guide slots 33 while changing the angle of the steering column 20 which is secured to the movable bracket 40.

[0045] Further, a locking unit 60 is provided on a predetermined portion of the connection rod 50. The locking unit 60 presses the first support bracket 31 to the movable bracket 40 to increase friction between the first and second brackets 31 and 32 and the movable bracket 40. Thus, the movable bracket 40 is locked to the first and second support brackets 31 and 32. In this way, the steering column 20 is locked at a desired angle.

[0046] The locking unit 60 includes first and second stoppers 51 and 52, a rotary unit 70, and inner and outer movable units 81 and 82. The first and second stoppers 51 and 52 are respectively provided on opposite ends of the connection rod 50, to prevent the movable bracket 40 from being removed from the first and second support brackets 31 and 32. The rotary unit 70 is provided on a predetermined portion of the connection rod 50 between the first stopper 51 and the first support bracket 31. In this case, the rotary unit 70 is rotatably provided. Further, the inner and outer movable units 81 and 82 are provided so that the inner and outer movable units 81 and 82 and the rotary unit 70 support each other, and the inner and outer movable units 81 and 82 move along the connection rod 50 as the rotary unit 70 rotates, thus locking or unlocking the movable bracket 40 to or from the first and second support brackets 31 and 32.

[0047] The first stopper 51 is fastened to a first end of the connection rod 50 to be placed outside the first support bracket 31, in a screw-type fastening method. The second stopper 52 is integrally provided on a second end of the connection rod 50 to be placed outside the second support bracket 32. To fasten the first stopper 51 to the first end of the connection rod 50 in the screw-type fastening method, the first stopper 51 has an internal threaded part 51 a, and the connection rod 50 has an external threaded part 50 a on the first end thereof.

[0048] The rotary unit 70 includes a body 71 and a lever 72. The body 71 has at a central portion thereof a locking hole 71 a so that the connection rod 50 passes through the locking hole 71 a. The lever 72 extends from the body 71 to a predetermined height. The inner and outer movable units 81 and 82 are provided on right and left sides of the rotary unit 70, respectively. In this case, the inner movable unit 81 is provided at a predetermined position inside the rotary unit 70, while the outer movable unit 82 is provided at a predetermined position outside the rotary unit 70. Further, the inner and outer movable units 81 and 82 are provided to be symmetrical with each other relative to the rotary unit 70. The inner and outer movable units 81 and 82 respectively have locking holes 83 so that the connection rod 50 passes through the locking holes 83.

[0049] A first cam face 85 is provided on each of facing surfaces of the inner and outer movable units 81 and 82 which face the rotary unit 70. The first cam face 85 has an inclined part 84 which is inclined along a circumferential direction of the first cam face 85. Further, a second cam face 74 is provided on each of opposite surfaces of the rotary unit 70 which face the inner and outer movable units 81 and 82. The second cam face 74 has a pressing part 73 to press or release the inclined part 84 of the first cam face 85 according to a rotating direction of the rotary unit 70.

[0050] When the rotary unit 70 rotates in a direction to cause an operation of the pressing parts 73 of the second cam faces 74 of the rotary unit 70, in conjunction with the inclined parts 84 of the first cam faces 85 of the inner and outer movable units 81 and 82, the inner and outer movable units 81 and 82 move away from the rotary unit 70 in opposing directions. Because movements of the rotary unit 70 and the inner and outer movable units 81 and 82 along the connection rod 50 are limited by the first and second stoppers 51 and 52, the rotary unit 70 and the inner and outer movable units 81 and 82 move toward the first support bracket 31 by moving distances of the first and second movable units 81 and 82, thus pressing the first support bracket 31. Thus, the movable bracket 40 is in close contact with the first and second support brackets 31 and 32 to be locked to the first and second support brackets 31 and 32. On the other hand, when the rotary unit 70 rotates in a reverse direction, the inclined parts 84 are released from the pressing parts 73, and simultaneously, the first support bracket 31 is released from the locking unit 60. Thereby, the movable bracket 40 is unlocked from the first and second support brackets 31 and 32.

[0051] Although the first cam faces 85 may be provided on the opposite surfaces of the rotary unit 70 and the second cam faces 74 may be provided on the facing surfaces of the inner and outer movable units 81 and 82 which face the rotary unit 70, the inner and outer movable units 81 and 82 may move away from the rotary unit 70 by a rotation of the rotary unit 70. Thus, the first cam faces 85 may be provided on the opposite surfaces of the rotary unit 70 and the second cam faces 74 may be provided on the facing surfaces of the inner and outer movable units 81 and 82 which face the rotary unit 70. Preferably, the inclined part 84 may comprise a plurality of inclined parts and the pressing part 73 may comprise a plurality of pressing parts corresponding to the plurality of inclined parts, so as to allow the inner and outer movable units 81 and 82 to more stably and smoothly move.

[0052] Further, when the locking unit 60 is operated, and a torque generated by the rotation of the rotary unit 70 is transmitted to the inner and outer movable units 81 and 82 or to the connection rod 50, the inner and outer movable units 81 and 82 and the connection rod 50 rotate and thereby the inner and outer movable units 81 and 82 may not move away from the rotary unit 70 in opposing directions. Thus, in order to make the inner and outer movable units 81 and 82 move away from the rotary unit 70, the connection rod 50 and the inner and outer movable units 81 and 82 are provided so that the connection rod 50 and the inner and outer movable units 81 and 82 are prevented from rotating.

[0053] To prevent the connection rod 50 and the inner and outer movable units 81 and 82 from rotating, a first rotation preventing projection 81 a is provided on a surface of the inner movable unit 81 which is opposite to the first cam face 85, and the first rotation preventing projection 81 a is supported by the first support bracket 31. A second rotation preventing projection 52 a is provided on a predetermined portion of the second stopper 52 to be supported by the second support bracket 32. Further, a third rotation preventing projection 82 a is provided on a surface of the outer movable unit 82 which is opposite to the first cam face 85, and the third rotation preventing projection 82 a is supported by the first stopper 51. The first, second, and third rotation preventing projections 81 a, 52 a, and 82 a prevent the inner and outer movable units 81 and 82 and the connection rod 50 from rotating. Thus, when the rotary unit 70 rotates, the inner and outer movable units 81 and 82 rectilinearly reciprocate along the connection rod 50, but do not rotate.

[0054] Preferably, the first and second rotation preventing projections 81 a and 52 a are fitted into the guide slots 33 of the first and second support brackets 31 and 32, respectively, so that the first and second rotation preventing projections 81 a and 52 a are supported by the first and second support brackets 31 and 32, respectively, without any mounting member. Further, the first stopper 51 has a seat groove 51 b so that the third rotation preventing projection 82 a is seated in the first stopper 51.

[0055] A rotation restraining part 90 is provided on a predetermined portion of one of the rotary unit 70 and the inner and outer movable units 81 and 82 to prevent the rotary unit 70 from rotating when the movable bracket 40 is locked to the first and second support brackets 31 and 32.

[0056] The rotary unit 70 is restrained not to rotate by the rotation restraining part 90 when the movable bracket 40 is locked to the first and second support brackets 31 and 32, thus allowing a user to easily confirm whether the steering column 20 is locked at a desired angle or not.

[0057] The rotation restraining part 90 is provided at an edge of the inclined part 84 which is provided on the first cam face 85 to prevent the rotary unit 70 from rotating when the inner and outer movable units 81 and 82 move away from the rotary unit 70 to a maximum, thus allowing the user to easily confirm whether the steering column 20 is locked at the desired angle or not.

[0058] The inclined part 84 has a shape of a depression which is depressed on the first cam face 85, and the pressing part 73 has a shape of a projection which is projected from the cam face 74. The rotation restraining part 90 is provided between the edge of the inclined part 84, which is adjacent to the second cam face 74, and the first cam face 85.

[0059] To an inner surface of each of the first and second support brackets 31 and 32 are mounted crossing plates 100. Each of the crossing plates 100 is mounted to rotate around an end thereof, and has a crossing slot 101 to cross the guide slot 33 of each of the first and second support brackets 31 and 32, thus allowing the connection rod 50 to pass through the guide slot 33 and the crossing slots 101.

[0060] The crossing plates 100 allow the movable bracket 40 to be more firmly locked to the first and second support brackets 31 and 32, thus efficiently preventing the steering column 20 from popping up. The operation of the crossing plates 100 will be described in the following in detail.

[0061] When a large external impact due to the collision between vehicles acts on the steering column 20, a locking force of the locking unit 60 may be insufficient to reliably lock the movable bracket 40 to the first and second support brackets 31 and 32. Thereby, the steering column 20 may pop up. However, the tilt adjusting unit for steering columns according to the present invention is provided with the crossing plates 100, thus more efficiently preventing the steering column 20 from popping up.

[0062] In a detailed description, the crossing slot 101 is formed through each of the crossing plates 100 to cross the guide slot 33 of each of the first and second support brackets 31 and 32. Further, each of the crossing plates 100 has at an end thereof a rivet hole 103, and each of the first and second support brackets 31 and 32 has a rivet hole 34 at a position corresponding to the rivet hole 103 so that a rivet member 102 passes through the rivet holes 103 and 34. As such, since the rivet member 102 is fastened to each of the first and second support brackets 31 and 32 through the rivet holes 103 and 34, the crossing plates 100 are mounted to the first and second support brackets 31 and 32 to rotate around the rivet holes 103 and 34. In this case, the rivet members 102 having first ends are fitted into the rivet holes 103 and 34, and protruding ends thereof are pressed to form second ends.

[0063] Further, the connection rod 50 passes through the crossing slots 101 of the crossing plates 100. Thus, when the large external impact due to the collision between vehicles acts on the steering column 20 and a force of impact is larger than the locking force of the locking unit 50 which locks the movable bracket 40 to the first and second support brackets 31 and 32, the movable bracket 40 is apt to be released from the first and second support brackets 31 and 32. However, at this time, the crossing plates 100 rotate around the rivet holes 103 and 34, and rotating forces of the crossing plates 100 are applied to the connection rod 50. The rotating forces of the crossing plates 100 serve as a resistance against a movement of the connection rod 50 along the guide slots 33. Therefore, such a construction prevents an undesired movement of the movable bracket 40, and thereby preventing the steering column 20 from popping up.

[0064] In order to more efficiently prevent the steering column 20 from popping up using the crossing plates 100, a pair of crossing plates 100 which are inside and outside crossing plates 100 are provided to cross each other on a predetermined portion of each of the first and second support brackets 31 and 32. In the above state, a pair of rivet holes 34 are formed on each of the first and second support brackets 31 and 32 at positions on left and right sides of the guide slot 33. The pair of crossing plates 100 are rotatably mounted to the pair of rivet holes 34 of each of the first and second support brackets 31 and 32, respectively, by two rivet members 102 which are fitted into the aligned rivet holes 103 and 34, so that the pair of crossing plates 100 cross each other.

[0065] Each pair of crossing plates 100 which are placed to cross each other, rotate in opposing directions, when the movable bracket 40 moves. When the movable bracket 40 is locked to the first and second support brackets 31 and 32, the crossing plates 100 which cross each other more efficiently prevent the connection rod 50 from moving along the guide slots 33.

[0066] Further, when the first support bracket 31 is pressed by the locking unit 60 to lock the steering column 20 at the desired angle, the crossing plates 100 increase contact surface areas between the first support part 41 of the movable bracket 40 and the first support bracket 31, and between the second support part 41 of the movable bracket 40 and the second support bracket 32, thus allowing the movable bracket 40 to be more reliably locked to the first and second support brackets 31 and 32.

[0067] Further, on each of the first and second support brackets 31 and 32, a pair of friction plates 110 are respectively provided between the outside crossing plate 100 and the first or second support bracket 31 or 32, and between the inside and outside crossing plates 100. Each of the friction plates 110 has a through hole 111 at a central portion thereof so that the connection rod 50 passes through the through hole 111. The friction plates 110 increase contact surface areas between the first and second support brackets 31 and 32 and the movable bracket 40, in cooperation with the crossing plates 100, thus allowing the movable bracket 40 to be more reliably locked to the first and second support brackets 31 and 32, and thereby more efficiently preventing the steering column 20 from popping up.

[0068] According to the first embodiment of the present invention, the tilt adjusting unit for steering columns is provided with two movable units. But, the steering column 20 may be locked using a locking unit 60′ which has one movable unit. A tilt adjusting unit having one movable unit according to a second embodiment will be described in the following.

[0069] Since the general construction of the tilt adjusting unit according to the second embodiment remains the same as the tilt adjusting unit according to the first embodiment, except for a construction of the locking unit 60′, those elements common to the first and second embodiments will not be described herein in detail.

[0070] As shown in FIGS. 4 and 5, in the tilt adjusting unit for steering columns according to the second embodiment, the locking unit 60′ includes a rotary unit 70′ and one movable unit 81′ at predetermined positions between a first stopper 51′ and the first support bracket 31. The movable unit 81′ is provided between the rotary unit 70′ and the first support bracket 31. A bearing 120 is provided between the first stopper 51′ and the rotary unit 70′ to ensure a smooth rotation of the rotary unit 70′.

[0071] The rotary unit 70′ includes a body 71′ which has at a central portion thereof a locking hole 71 a′ so that the connection rod 50 passes through the locking hole 71 a′. A lever 72′ extends from the body 71′ to a predetermined height. Further, the movable unit 81′ has a locking hole 83′ at a central portion thereof so that the connection rod 50 passes through the locking hole 83′. First and second cam faces 85′ and 74′ are provided on facing surfaces of the movable unit 81′ and the rotary unit 70′, respectively. In this case, the first cam face 85′ has an inclined part 84′, and the second cam face 74′ has a pressing part 73′. Alternatively, the first and second cam faces 85′ and 74′ may be respectively provided on the facing surfaces of the rotary unit 70′ and the movable unit 81′. Further, the inclined part 84′ comprises a plurality of inclined parts, and the pressing part 73′ comprises a plurality of pressing parts corresponding to the plurality of inclined parts, thus allowing the movable unit 81′ to stably move.

[0072] Similarly to the first embodiment, when the rotary unit 70′ rotates in a direction, the inclined parts 84′ are pressed by the pressing parts 73′ and the movable unit 81′ moves away from the rotary unit 70′. At this time, the rotary unit 70′ and the movable unit 81′ move toward the first support bracket 31 by the first stopper 51′ while pressing the first support bracket 31, thus locking the movable bracket 40 to the first and second support brackets 31 and 32. On the other hand, when the rotary unit 70′ rotates in a reverse direction in such a state, the inclined parts 84′ are released from the pressing parts 73′ and the movable unit 81′ returns to an original position thereof. Thereby, the movable bracket 40 is unlocked from the first and second support brackets 31 and 32.

[0073] Further, a rotation restraining part 90′ is provided at an edge of each of the inclined parts 84′ which are provided on the first cam face 85′, thus preventing the rotary unit 70′ from rotating when the steering column 20 is locked. According to the second embodiment of the present invention, each of the inclined parts 84′ has a shape of a projection which is projected from the first cam face 85′, and each of the pressing parts 73′ has a shape of a hole which is formed through the rotary unit 70′ to receive the corresponding inclined part 84′, thus pressing the inclined part 84′ when the rotary unit 70′ rotates. The rotation restraining part 90′ extends from the edge of the inclined part 84′, which is adjacent to the second cam face 74′, into the pressing part 73′.

[0074] Thus, before the steering column 20 is locked, each of the inclined parts 84′ is placed in the corresponding pressing part 73′. As the rotary unit 70′ rotates in a direction, each of the inclined parts 84′ moves to an outside of the corresponding pressing part 73′, so that the movable unit 81′ moves away from the rotary unit 70′. When the rotary unit 70′ continuously rotates in such a state, an edge of each of the pressing parts 73′ which has the shape of the hole is stopped by each of the rotation restraining parts 90′ which extends into each of the pressing parts 73′. In this case, the movable unit 81′ moves away from the rotary unit 70′ to a maximum and thereby the movable bracket 40 is locked to the first and second support brackets 31 and 32. In such a state, because the edge of each of the pressing parts 73′ is stopped by each of the rotation restraining part 90′, the rotary unit 70′ does not rotate any more, thus allowing the user to easily confirm whether the steering column 20 is locked at the desired angle or not.

[0075] In the tilt adjusting unit according to the second embodiment, the movable unit 81′ and the connection rod 50 are prevented from rotating by a torque which is generated by a rotation of the rotary unit 70′ when the locking unit 60′ is operated, similarly to the tilt adjusting unit of the first embodiment. To prevent the movable unit 81′ and the connection rod 50 from rotating, a first rotation preventing projection 81 a′ is provided on a surface of the movable unit 81′ which is opposite to the first cam face 85′, and the first rotation preventing projection 81 a′ is supported by the first support bracket 31. Further, a second rotation preventing projection 52 a is provided on a predetermined portion of the second stopper 52 to be supported by the second support bracket 32. The first and second rotation preventing projections 81 a′ and 52 a prevent the movable unit 81′ and the connection rod 50 from rotating. Thus, the movable unit 81′ only rectilinearly reciprocates along the connection rod 50.

[0076] The first and second rotation preventing projections 81 a′ and 52 a are fitted into the guide slots 33 of the first and second support brackets 31 and 32, respectively, so that the first and second rotation preventing projections 81 a′ and 52 a are supported by the first and second support brackets 31 and 32, respectively, without using any mounting member.

[0077] In the locking unit 60, 60′ according to the first and second embodiments, the rotary unit 70, 70′ and the movable units 81 and 82, 81′ are provided between the first stopper 51, 51′ and the first support bracket 31. However, when the movable unit 81 and 82, 81′ and the connection rod 50 are provided to be prevented from rotating, the rotary unit 70, 70′ and the movable unit 81 and 82, 81′ may be provided between the second stopper 52 and the second support bracket 32, or between the first and second support brackets 31 and 32 and the movable bracket 40, or between the first and second support parts 41 of the movable bracket 40. Thus, as the rotary unit 70, 70′ rotates, the movable unit 81 and 82, 81′ moves away from the rotary unit 70, 70′ and thereby the movable bracket 40 is supported by the first and second support brackets 31 and 32.

[0078] The operation and operational effect of the tilt adjusting unit for steering columns according to the present invention will be described in the following in detail, with reference to FIGS. 6 and 7. Since the crossing plates 100 and the friction plates 110 of the first embodiment are operated in a same manner as the crossing plates 100 and the friction plates 110 of the second embodiment, and the general operation of the locking unit 60′ of the second embodiment is very similar to the general operation of the locking unit 60 of the first embodiment, the operation and operational effect of the tilt adjusting unit for steering columns according to the present invention will be described in the following with reference to only the first embodiment.

[0079] First, after the angle of the steering column 20 is appropriately adjusted, the user rotates the rotary unit 70 in a direction using the lever 72. At this time, each of the pressing parts 73 provided on the second cam face 74 moves along each of the inclined parts 84 of the first cam face 85 until being stopped by the rotation restraining part 90 which is provided at the edge of each of the inclined parts 84. Further, the inner and outer movable units 81 and 82 move away from the rotary unit 70 in opposing directions to the maximum. In this case, because the first stopper 51 is fixed not to move, the rotary unit 70 and the inner and outer movable units 81 and 82 which are provided between the first support bracket 31 and the first stopper 51, move along the connection rod 50 toward the first support bracket 31 by a distance between the inner and outer movable units 81 and 82 which move away from the rotary unit 70 in opposing directions, and thereby press the first support bracket 31. Therefore, the first and second support brackets 31 and 32 come into close contact with the first and second support parts 41 of the movable bracket 40, respectively. The movable bracket 40 is locked to the first and second support brackets 31 and 32, and the steering column 40 which is secured to the movable bracket 40 is also locked. At this time, because each of the pressing parts 73 is stopped by the rotation restraining part 90 which is provided at the edge of each of the inclined parts 84, the rotary unit 70 does not any rotate more although the lever 72 is operated, thus allowing the user to reliably confirm whether the steering column 20 is locked or not.

[0080] When a large impact exceeding the locking force of the locking unit 60 due to the collision between vehicles, acts on the steering column 20, the steering column 20 is apt to be released from a locked position. However, at this time, as shown in FIG. 6, the pair of crossing plates 100 which are mounted to each of the first and second support brackets 31 and 32 rotate in opposing directions, thus biasing the connection rod 50 in rotating directions of the crossing plates 100 to prevent the connection rod 50 from moving along the guide slot 33. Thereby, a force to support the connection rod 50 to the first and second support brackets 31 and 32 is increased by the crossing plates 100, and the movable bracket 40 is continuously locked to the first and second support brackets 31 and 32. Further, the friction plates 110 increase the contact surface areas between the first and second support brackets 31 and 32 and the movable bracket 40, together with the crossing plates 100, thus allowing the movable bracket 40 to be more reliably locked. In the present invention, the locking unit 60, the crossing plates 100, and the friction plates 110 prevent the steering column 20 from popping up, so that the steering column 20 is held at the locked position. The reference numeral 130 denotes an elastic member to elastically support the connection rod 50 to each of the first and second support brackets 31 and 32.

[0081] Meanwhile, when the user desires to re-adjust the angle of the steering column 20 which is locked as described above, the user rotates the rotary unit 70 using the lever 72 in a direction which is opposite to a rotating direction of the rotary unit 70 to lock the steering column 20. At this time, each of the pressing parts 73 of the second cam face 74 moves along each of the inclined parts 84 of the first cam face 85 in a direction away from the rotation restraining part 90. In this case, the inner and outer movable units 81 and 82 return to original positions thereof, while the movable bracket 40 is unlocked from the first and second support brackets 31 and 32, so that the movable bracket 40 moves along the guide slots 33. In this way, the angle of the steering column 20 is adjusted again. When the angle of the steering column 20 is adjusted, the crossing plates 100 rotate in opposing directions together with a movement of the connection rod 50 along the guide slots 33, as shown in FIG. 7.

[0082] As is apparent from the above description, the present invention provides a tilt adjusting unit for steering columns, which is provided with crossing plates to more reliably lock a steering column in cooperation of a locking unit, thus preventing the steering column from popping up. Further, according to the present invention, the tilt adjusting unit is provided with friction plates to increase contact surface areas between a movable bracket and support brackets, thus more efficiently preventing the steering column from popping up. In the tilt adjusting unit of the present invention, the locking unit is provided with a rotation restraining part, thus allowing a user to easily confirm whether the steering column is locked or not.

[0083] Although a few preferred embodiments of the present invention have been shown and described, it would be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents. 

What is claimed is:
 1. A tilt adjusting unit for steering columns, comprising: a support bracket mounted to a predetermined portion of a vehicle body; a steering column mounted to a predetermined portion of the vehicle body to tilt relative to the vehicle body; a movable bracket to tilt along with the steering column; a connection rod to connect the movable bracket to the support bracket; a guide slot formed on a predetermined portion of the support bracket along a tilting direction of the steering column, with the connection rod passing through the guide slot; a locking unit provided on a predetermined portion of the connection rod to lock or unlock the movable bracket to or from the support bracket; and a crossing plate mounted to a predetermined portion of the support bracket to rotate around an end of the crossing plate, the crossing plate having a crossing slot to cross the guide slot, thus allowing the connection rod to pass through both the guide slot and the crossing slot.
 2. The tilt adjusting unit according to claim 1, wherein the crossing plate comprises a pair of crossing plates which cross each other.
 3. The tilt adjusting unit according to claim 2, wherein the pair of crossing plates rotate in opposing directions, when the movable bracket tilts.
 4. The tilt adjusting unit according to claim 1, wherein the locking unit comprises: first and second stoppers provided on opposite ends of the connection rod, respectively, to prevent the movable bracket from being removed from the support bracket; a rotary unit rotatably provided on a predetermined portion of the connection rod between the first and second stoppers; a movable unit provided on a predetermined portion of the connection rod so that the movable unit and the rotary unit support each other, the movable unit moving along the connection rod as the rotary unit rotates, thus locking or unlocking the movable bracket to or from the support bracket; and a rotation restraining part provided on a predetermined portion of either the rotary unit or the movable unit to prevent the rotary unit from rotating when the movable bracket is locked to the support bracket.
 5. The tilt adjusting unit according to claim 4, further comprising: a first cam face provided on one of facing surfaces of the rotary unit and the movable unit which face each other, the first cam face having an inclined part which is inclined along a circumferential direction of the first cam face; and a second cam face provided on a remaining one of the facing surfaces of the rotary unit and the movable unit which face each other, the second cam face having a pressing part to press or release the inclined part according to a rotating direction of the rotary unit.
 6. The tilt adjusting unit according to claim 5, wherein the rotation restraining part is provided at an edge of the inclined part to stop the pressing part.
 7. The tilt adjusting unit according to claim 6, wherein the inclined part has a shape of a depression which is depressed on the first cam face, the pressing part has a shape of a projection which is projected from the second cam face, and the rotation restraining part is provided between the edge of the inclined part, which is adjacent to the second cam face, and the first cam face.
 8. The tilt adjusting unit according to claim 6, wherein the inclined part has a shape of a projection which is projected from the first cam face, the pressing part is provided to receive the inclined part therein, and the rotation restraining part extends from the edge of the inclined part, which is adjacent to the second cam face, into the pressing part.
 9. The tilt adjusting unit according to claim 5, wherein the inclined part comprises a plurality of inclined parts, and the pressing part comprises a plurality of pressing parts corresponding to the plurality of inclined parts.
 10. The tilt adjusting unit according to claim 5, wherein the movable unit and the connection rod are provided to be prevented from rotating.
 11. The tilt adjusting unit according to claim 5, wherein the movable unit comprises a pair of movable units provided on opposite sides of the rotary unit, the pair of movable units comprising: an inner movable unit provided at a predetermined position inside the rotary unit; and an outer movable unit provided at a predetermined position outside the rotary unit.
 12. The tilt adjusting unit according to claim 5, wherein the movable unit is provided between the rotary unit and the support bracket.
 13. The tilt adjusting unit according to claim 12, further comprising a bearing provided on a side of the rotary unit which is opposite to the movable unit.
 14. The tilt adjusting unit according to claim 4, further comprising a lever provided on a predetermined portion of the rotary unit.
 15. The tilt adjusting unit according to claim 1, further comprising a friction plate provided between the movable bracket and the support bracket to increase a contact surface area between the movable bracket and the support bracket.
 16. The tilt adjusting unit according to claim 3, further comprising: a first friction plate provided between the support bracket and one of the pair of crossing plates; and a second friction plate provided between the pair of crossing plates, the first and second friction plates increasing contact surface areas between the support bracket and the pair of crossing plates. 